Gringo, I think Shy makes some pretty good points here. With a fire indication and an actual fire, 5 minutes could mean losing the ability to control the airplane. Whereas an overweight landing if executed properly should cause hot brakes and some MX inspections, not a burning catastrophe. I'm not second guessing the crew because I wasn't there, but isn't the overweight landing scenario you're describing a little bit dramatic?
Also maybe some whale drivers can chime in here, but a 74 doing a trans Atlantic wouldn't be that heavy (relatively) would it?
-HP